Entamoeba histolytica

Entamoeba histolytica is one of a number
of species of small amoebae which live in the
alimentary canal of humans. These are usually
harmless protozoa, feeding on bacteria and
particles in the intestine. In certain conditions,
entamoeba invades the wall of the intestine or
rectum causing ulceration and bleeding, with
pain, vomiting and diarrhoea, symptoms of
amoebic dysentery.